CPU Comparison
Intel Core i5-8400 vs Intel Core i3-8350K
A side-by-side comparison of specs, performance and value. The Intel Core i5-8400 is a landmark mainstream desktop processor that fundamentally shifted the budget CPU market by bringing six physical cores to the i5 tier for the first time.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Handles office tasks and moderate programming workloads efficiently.
Overclocking does not add threads. For heavily threaded productivity work, a stock 6-core CPU will easily beat an overclocked 4-core i3.
Gaming
Capable of smooth 1080p gaming when paired with a mid-range discrete GPU.
At stock speeds, it is comparable to other 8th-gen i3s. When overclocked to 5.0 GHz+, it can match stock i5s in eSports titles, but the lack of threads hurts in modern AAA games.
Virtualization
Good for basic VMs, but 6 threads limit heavy parallel virtualization.
4 threads is a hard limit for virtualization, regardless of how fast those threads run.
Efficiency
Balanced performance within a standard 65W power envelope.
Terrible efficiency. Pushing 1.3V+ through 14nm silicon to hit 5.0 GHz results in massive power draw and heat.
Specialized Performance
AI / ML
- No AI-specific hardware
- CPU inference is slow due to lack of threads
- No AI acceleration
- High clock speed cannot compensate for lack of AI instructions
Content Creation
Gaming
- Excellent for budget gaming builds
- Handles eSports titles flawlessly
- May bottleneck high-end modern GPUs at 1080p
- Requires heavy overclocking to be relevant
- High clock speeds benefit older eSports titles
- 4 cores/4 threads is a severe limitation for modern AAA gaming
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Disruptive price-to-performance ratio
- 6 physical cores for modern gaming
- Includes integrated UHD Graphics 630
- Standard 65W TDP is easy to cool
- Wide compatibility with 300-series motherboards
Cons
- No Hyper-Threading (only 6 threads)
- Locked multiplier prevents overclocking
- End-of-life platform (LGA 1151)
- Officially limited to DDR4-2666
- Not supported by Windows 11 officially
Pros
- First unlocked i3, historic significance
- Massive overclocking headroom (5.0 GHz+ on air)
- 8MB L3 cache aids high-frequency stability
- Fun project chip for hardware enthusiasts
- High stock clock of 4.0 GHz
Cons
- No Hyper-Threading (4 cores, 4 threads only)
- Requires expensive Z-series motherboard
- Terrible power efficiency when overclocked
- Outperformed by cheaper locked 6-core CPUs
- Obsolete LGA 1151 v2 platform
Competitors & Alternatives
Intel Core i5-8400
- AMD Ryzen 5 1600Rival
Mainstream Desktop
- Compare head-to-headIntel Core i5-7500Rival
Mainstream Desktop
- AMD Ryzen 5 2600Rival
Mainstream Desktop
- Intel Core i7-7700Rival
Mainstream Desktop
- AMD Ryzen 5 2400GRival
Mainstream Desktop
Slightly newer generation with marginally higher clocks.
Compare head-to-headNewer platform with 8 threads and similar gaming performance.
Compare head-to-headLow power alternative for SFF builds.
Compare head-to-head
Intel Core i3-8350K
- AMD Ryzen 3 1300XRival
Budget Desktop
- AMD Ryzen 5 1600Rival
Mid-Range Desktop
- Compare head-to-headIntel Core i5-8400Rival
Mid-Range Desktop
- Intel Core i3-8350KRival
Budget Enthusiast
- AMD Ryzen 5 2600Rival
Mid-Range Desktop
- AMD Ryzen 5 3600Alt
Offers 12 threads and modern platform features, destroying the 8350K in productivity and gaming for less total cost.
If you want to overclock on LGA 1151 v2, this gives you 6 cores to play with.
Compare head-to-headA modern budget king that doesn't need an expensive motherboard to perform well.
Compare head-to-head- AMD Ryzen 3 3100Alt
Offers 8 threads and PCIe 4.0 on a budget platform, making the 8350K obsolete.
Our Verdict on Each
A legendary value CPU that forced the market to adopt 6 cores as the standard. Excellent for budget gaming, though lacking Hyper-Threading.
Best for: Upgrading an older LGA 1151 system on a budget, or building an office/HTPC machine.
Read the full reviewA fun overclocking toy in 2017, but the lack of Hyper-Threading and a high 91W TDP make it a poor value compared to even cheap modern chips.
Best for: You should avoid buying the Intel Core i3-8350K unless you are a dedicated overclocking hobbyist looking for a cheap project chip to practice manual tuning, delidding, or extreme cooling on. If you fall into that niche, buying a used 8350K for $20 and pushing it to 5.0 GHz can be incredibly fun and educational. However, for any practical use case—gaming, work, or productivity—this chip is a poor investment. It requires an expensive Z370 or Z390 motherboard to utilize its only feature (overclocking), yet a locked Ryzen 5 3600 on a cheap B450 board will destroy it in every multi-threaded benchmark while using less power. The lack of Hyper-Threading is a fatal flaw that no amount of frequency can fix. Spend your money on modern hardware.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-8400 or Intel Core i3-8350K?
Based on our editorial ratings, the Intel Core i5-8400 comes out ahead with a score of 8.5/10. That said, the best choice depends on your workload — check the spec and performance breakdown above for gaming, productivity and efficiency differences.
Which is faster for gaming, Intel Core i5-8400 or Intel Core i3-8350K?
For gaming, the Intel Core i5-8400 leads with a gaming performance score of 78/100 among Intel Core i5-8400 and Intel Core i3-8350K.
Which uses less power?
The Intel Core i5-8400 has the lowest rated TDP. Power draw across these chips: Intel Core i5-8400 (65 W), Intel Core i3-8350K (91 W).
Do Intel Core i5-8400 and Intel Core i3-8350K use the same socket?
No. They use different sockets (Intel Core i5-8400: Intel Socket 1151, Intel Core i3-8350K: LGA 1151), so each needs a compatible motherboard.
Which has more cores?
The Intel Core i5-8400 has the most cores. Core counts: Intel Core i5-8400 (6 cores), Intel Core i3-8350K (4 cores).